The Korea Customs Service said Thursday that it intercepted 5.6 kilograms of illicit drugs in 10 international mail cases from April to July using a newly established secondary screening network. The agency said controlled deliveries helped investigators arrest all suspects involved. The crackdown is part of a broader effort to strengthen border controls through layered enforcement.

Korea Customs Service Commissioner Lee Jong-wook speaks at a press briefing on drug enforcement results at the Government Complex Sejong, Thursday. Yonhap

The Korea Customs Service (KCS) intercepted 5.6 kilograms of illicit drugs in 10 separate cases involving international mail from April to July through a newly established secondary screening network, the agency said Thursday.

In particular, it used controlled deliveries, a covert investigative technique, to track the shipments, resulting in the arrest of all suspects involved.

The new method involves a dual-layer drug screening system established in cooperation with Korea Post in April. Under the system, international mail that passes initial inspections at the border is subject to additional screening at one of five major postal distribution centers nationwide.